Now another rich guy has joined the million dollar charity challenge. This time, however, it's Trump who's getting "double dog dared" to do something for money.

Outspoken Dallas Mavericks owner and star of ABC's 'Shark Tank' Mark Cuban appeared on a Dallas news program and issued his own interesting challenge to the star of NBC's 'The Apprentice.' First, he characterized Trump's offer to the President as "one of the dumbest things ever." Then he talks about how he's thought about issuing his own high priced bet to the man with the undead toupee. That's when Cuban looks into the camera and says simply, "Donald, you shave your head, $1 million to any charity you want."

This isn't the first time Trump has been hit with such an offer. 'Colbert Report' host and American patriot Stephen Colbert issued his own challenge to Trump shortly after Trump issued his to the President. Colbert promised to give Trump $1 million from his "Colbert Super PAC" if Trump would allow Colbert to, um, place a certain part of his male anatomy in Trump's mouth. We're assuming that means both of them have to be in Trump's pie hole in order for it to count. Trump has yet to respond to either offer.